I am trying to sweep a cut around a boss, and I'm struggling mightily to make it work.  The path is defined by intersecting a helical surface with some extruded surfaces.  Any idea what is going on here?  The places where the cut hiccups are not even at transition points between the different parts of the profile.  And it doesn't actually follow the profile.  And it terminates early.

The swx2013 model is attached.

Thanks in advance for any help.